Chapter 4

Question 1

Elastic Deformation

Answer 1

Temporary change in shape

Question 2

Plastic Deformation

Answer 2

Permanent change in shape

Question 3

Strength

Answer 3

The maximum force a material can withstand before failiure. Same as fracture point.

Question 4

Strong

Answer 4

A large stress is required to cause failiure

Question 5

Weak

Answer 5

Opposite of strong

Question 6

Toughness

Answer 6

Energy absorbed per unit volume J/m^2

Question 7

Tough

Answer 7

A material that undergoes a lot of plastic deformation before breaking

Question 8

Brittle

Answer 8

Opposite of tough. Breaks soon after the elastic limit

Question 9

Hard

Answer 9

Resistant to dents and scratches. Measured in Pa.

Question 10

Ductile

Answer 10

Can be easily drawn into a wire

Question 11

Malleable

Answer 11

Can be easily hammered of pressed into a shape

Question 12

Stress

Answer 12

Force/area

Question 13

Strain

Answer 13

Extension/original length.

A measure of how much an object is being stretched.

Question 14

Young Modulus

Answer 14

Stress/Strain

Measure of the stiffness of a material.

Question 15

Yield Stress

Answer 15

The level of stress when a material undergoes plastic deformation. Same as elastic limit. Mathematical form
ax+by=c

Question 16

Resistance

Answer 16

How hard it is for electricity to flow.
R=V/I
Unit: Ohms

Question 17

Conductance

Answer 17

Opposite of resistance-how easy it is for electricity to flow.
G=1/R OR G=I/V
Unit: Siemens (S)

Question 18

Resistivity

Answer 18

A material constant used to work out resistance.
Resistivity=RA/L
Unit: Ohm Metre

Question 19

Conductivity

Answer 19

Opposite of resistivity

Conductivity=1/Resistivity